1. Field of the Invention
This invention relates to two-axis and other lathes and in particular relates to a multiple tool holding device for use on lathes.
2. Description of the Related Art
Lathes are machine tools that are used to rotate a work piece on its axis to perform a variety of operations, including outer diameter (O.D.) work piece operations such as roughing, finishing, profiling, grooving, threading, and parting off, and inner diameter (I.D.) work piece operations such as boring. Lathes include conventional lathes, NC (numerically controlled) lathes, CNC (computer numerically controlled) lathes, multi-tasking lathes and multi-axis lathes.
The tools are applied to the work piece to create an object on the lathe which has symmetry about an axis of rotation of the work piece. Material is removed from the work piece using a hardened cutting tool, which is usually fixed to a solid moveable mounting which is moved against the work piece by hand-control or computer-controlled motors. Cutting fluid is often pumped to the cutting site to cool and lubricate the cut and to wash away the resulting debris.
In a simple lathe, a carriage holds a tool bit and moves it longitudinally or perpendicularly to the work piece. The tool bit is mounted in a tool post, and in the prior art there is one tool bit per tool post, requiring changing of the tool bit for different types of cuts. Typical tools attached to metal lathes are long-shanked tools. Typically, tool bits are non-rotary cutting tools used in metal lathes. The cutting edge is ground to suit a particular machining operation and may be resharpened or reshaped as needed. The ground tool bit is held rigidly by a tool holder while it is cutting.
Typically, tools on a lathe are square shank tools for O.D. turning, for example 1-inch square shanks. Although some of the companies that provide lathe supplies (e.g., Kennametal, Iscar, Ingersol, Sanvik, Dorian, Mitsubishi, Widia, and Seco) have models in which the square shank tools are quickly interchangeable on the square-shank tool holders, these prior models do require changing of the tool, and resultant down-time for each change of tool to make possible a different type of cutting of the metal.
Generally, when a lathe is used to form a particular work piece, multiple tool bits, and therefore multiple tool holders must be used for the variety of cuts needed to form the finished piece. If it is desired to do operations not possible with tools already on a lathe, the tool holders on the lathe must be removed and replaced with a tool holder having the desired tool. Changing tool holders multiple times can substantially lengthen the time to finish tooling a work piece, and thus can increase the cost of the final work piece.
When a new tool holder is installed on a lathe, the new tool holder must be aligned (touched off) so that it is in the exact geometrical alignment site of the prior tool holder with respect to the work piece so that the cuts with the second tool holder are repeatable. In other words, x+z axis geometry offsets must be reset for each new tool.
It is therefore an object of the invention to provide a multiple tool-holding device for a two-axis lathe that reduces the number of tool changing operations and therefore the time and cost to produce a finished work piece. In addition, the invention further decreases downtime by repeating x, y and z geometry offsets, regardless of the tool type to which the tool-holding device is being changed.
It is a further object of the invention to provide a tool-holding device that can be used to replace any square shank tools on any two-axis lathe or turning center. By simple tailoring of the construction of the base of the invention for each particular lathe, the invention herein is usable on all lathes models, for example, turret and engine lathes, and all levels of machine including conventional lathes, NC lathes, CNC lathes, multi-tasking lathes and multi-axis lathes.
Other objects and advantages will be more fully apparent from the following disclosure.